Objectives: To determine the effectiveness of a group acceptance and commitment therapy (ACT) programme on improving psychological flexibility, resilience, and other psychological outcomes in adolescents with subclinical mental health issues in secondary schools in Hong Kong.
Methods: This study used a single-group, pretest-posttest, quasi-experimental design. The group ACT programme comprised four 1.5-hour sessions delivered weekly by a psychologist and an assistant. Students with subclinical levels of anxiety symptoms, depressive symptoms, or perceived stress were recruited from seven schools. Participants were asked to complete a self-report questionnaire before and after intervention to evaluate the effectiveness of the group ACT programme. Psychological flexibility was assessed using the Chinese version of the Acceptance and Action Questionnaire II. Resilience was assessed using the Short Resilience Scale. Anxiety and depressive symptoms were assessed using the Patient Health Questionnaire-9 and Generalised Anxiety Disorder-7, respectively. Life satisfaction was assessed using the Satisfaction with Life Scale. Sleep quality over the previous month was assessed using the Pittsburgh Sleep Quality Index.
Results: In total, 61 students of grades 7 to 12 were included; 53 (86.9%) attended ≥3 sessions. No significant changes were observed in psychological flexibility or resilience. Participants reported significantly reduced stress (p = 0.003) and depressive symptoms (p = 0.036), with a small-to-moderate effect size (Cohen's d = 0.36 and 0.28, respectively).
Conclusion: This school-based ACT programme appeared feasible and could significantly reduce stress and depressive symptoms among secondary school students with subclinical mental health issues.
Keywords: Acceptance and commitment therapy; Adolescent wellbeing; Anxiety; Depression; Preventive health services.